Patent GB-521802-A (GB)
Title: Improvements in or relating to telephone or like systems
IPC: H04Q1/26
Filed: 1938-11-24
Abstract: 521,802. Automatic exchange systems. AUTOMATIC TELEPHONE & ELECTRIC CO., Ltd., and HOPLEY, H. E. Nov. 24, 1938, No. 34211. [Class 40 (iv)] Signalling between a control office A and a routiner at an unattended office B is effected over a pair of junctions 10, 11 and 12, 13. Such signalling may be effected' by controlling earthed rectifier-polarized relays over the separate wires but as shown when a signal is to be sent over the former junction the receiving relays RR, RN (or 2RR, 2RN) are disconnected from the junction by SP (or 2SP) and one of two sending relays SN or SR (or 2SN or 2SR) which are oppositely connected to battery and ground is connected to the junction. This relay pulls up in series with the corresponding receiving relay at the other end of the junction and the stepping magnets SM, 2SM of switches S, 2S at the respective offices are energized. The operation of SP (or 2 SP) also causes relays IR and IQ (or 2IR and 2IQ) to interact to produce periodic interruption of the junction so that the sending and receiving relays are periodically released and the switches S, 2S step together. In certain positions relay RV (or 2RV) may replace the normal sending relay SN ( or 2SN) by the reverse sending relay (SR or 2SR) and the reverse receiving relay at the other end is thus actuated in appropriate positions and causes characteristic signals to be given. The switches S, 2S continue to be stepped in synchronism whether the reverse relays are operated or, not and after a cycle of 5 steps are automatically sent home. A single signal corresponding to position 1 of the switches is sent from B to A without moving them off normal. Signals over the other junction are effected by means of single positive or negative impulses. Normal control of routiner. On the operation of the start key KS relays H, HA pull up and relay SP starts a , signalling cycle of the synchronous switches. In position 2, RV pulls up and SR, 2RR operate ST, 2ST respectively. Relays 2PU, 2VU, 2RU are operated when 'the routiner' receives the start signal and are released when the main distributer and the vertical and rotary markers associated there- 2S2 to step on the distributer and access switches respectively move off normal. When 2S reaches its home position therefore circuits are made for 2SP, 2RV, and the synchronous switches run through a cycle, reverse impulses being sent from B to A in positions 1 to 3, and being repeated respectively to the magnets of switches R, V, P to light lamps RIL, VIL and PIL and so indicate which switch is being tested. At the rural office impulses are sent. over wiper 2S2 to step on the distributer and access switches and relays RU, VU, PU then fall back so that 2SP is not re-operated when the switch reaches its home position after the signalling cycle. When the routiner is ready to begin the -first test it energizes 2TF which connects the relay 2TS to the lower junction. Relay TS at the control office and 2TS pull up in series -and an impulse is sent over lead 15 to step on the test selecting switch and so cause TF, TS, 2TS to fall back. Magnet TM which was energized by TS then steps on switch T to light the first test-indicating lamp TIL 1. At the conclusion of the test TF re-operates to initiate the second test and cause the test indicating switch to be stepped on as before. When the first switch has been completely tested, 2RU pulls up and energizes 2SP, 2RV, a reverse impulse is sent over the junction to step the indicating switch R, and an impulse is sent locally over 2S2 to cause the next switch for test to be marked to the access switch. The synchronous switches remain stationary. When it is necessary to operate the vertical marking and distributer switches and indicators 2SN, RN operate initially in series and the switches run through a cycle reverse impulses being sent back in positions 2 and 3 of switches 2S, S. When all the switches have been tested relay 2RF is operated and causes the transmission of a signal pulse over the fourth position of 2S to cause RF at the control office to light the " Routine finished " lamp RFL. Continuous routine of particular switch. The operation of key KCR produces the same effects as the operation of KS except that the reverse signal is sent out over the upper junction in position 2 of S. In consequence 2CR, CR are operated instead of 2ST, ST and the "Continuous routine" lamp CRL is lit. The distributer and vertical and rotary marking switches are then controlled by keys KPS, KVS, KRS, which at each operation cause operation respectively of PS and 2PS, VS and 2VS over the lower and SR and 2SR over the upper junction to cause the switch-indicating and distributing switches to move to the appropriate positions. Key KS is then actuated to cause the routining operation to begin. At the end of the 'test cycle 2RU is not operated and the distributing and indicating switches are not moved. On the restoration of KCR, SP pulls up and the S switches are stepped. Cancel relays CRR, 2CRR are operated and release relays CR, SCR. Similarly when KS is restored STR, 2STR are operated to release ST, 2ST. If a fault is encountered the routiner stops and 2AX is operated. This initiates a cycle of the S switches and causes a reverse pulse to be sent in position 5 to operate AX which flickers the operative test-indicating lamp. To repeat a test on a faulty switch, KR is operated to energize RE. This starts an S-switch cycle and causes the reverse' pulse 'to be sent in position 4 and so cause a temporary operation of RES and 2RE. Relay H is thus released and REA which operates and releases sluggishly releases RE. AX falls, the test switch goes home and in due course the test cycle begins again. To resume the routine without clearing a fault key KSO is operated and SO, 2SO co-operate with SOS, SOA to cause the distributer and indicating switches to take a step. Operation under local control. Operation of the start key 2KS or continuous routine key 2KCR at B energizes 2AR which disconnects the upper signalling junction and sends a signal over the lower to operate AR and cause the local routine lamp LRL to glow at A.